The present invention relates to a magnetic recorder and/or reproducer having a standard record mode and a "long time" record mode. More particularly, the present invention relates to a magnetic recorder and/or reproducer for preventing crosstalk which may occur between adjacent tracks due to the use of a wide head in the long time record mode.
Generally speaking, a magnetic recorder and/or reproducer (e.g., a video cassette recorder) has a long time record mode whose record time is a predetermined multiple (two or three times) of the record time of the standard record mode. Specifically, the recording time of a long play (LP) mode is twice that of the standard record mode, and the recording time of a super long play (SLP) mode is three times as long as the record time of the standard record mode. A quad head (also called a "double azimuth quad head") video cassette recorder, which has the above standard and long time record modes, includes a rotation drum, a pair of standard record heads disposed on the rotation drum for recording and/or reproducing in the standard record mode, and a pair of long time record heads disposed on the rotation drum for recording and/or reproducing in the LP and SLP record modes.
The record track width for the long time record mode is narrower than the record track width for the standard record mode. Accordingly, the width of the long time record head is narrower than the width of the standard record head. In the standard record mode, the standard record head width is the same as the standard record track width. However, in the long time record mode, if the width of the long time record head is the same as the long time record track width, a tracking error can easily occur when a special reproduction operation is performed. Therefore, a long time record head whose width is greater than that of the long time record track is employed.
However, when the above-described wide head (i.e. long time record head) is utilized, portions of the signals of one track are recorded (superposed) on adjacent tracks. As a result, crosstalk occurs due to this superposed portion of the signal, and the signal-to-noise ratio decreases.
Meanwhile, U.S. Pat. No. 4,757,408 discloses a magnetic recorder and/or reproducer which comprises a flying erase head on a rotating drum in a dual-head video cassette recorder whose operation is based on track pitch and head width. The video cassette recorder has an editing function for inserting data into the existing information contained on a recorded tape. Thus, during the editing function, new data can be inserted without deleting the existing information when the video cassette recorder is operating in either the standard record mode or one of the long time record modes (LP or SLP mode ).